The Diagnostic and Statistical Manual, fourth edition, text revision [American Psychiatric Association. DSM-IV-TR, Washington, 2000] - or the DSM-IV-TR for short - describes Axis II personality disorders as "deeply ingrained, maladaptive, lifelong behavior patterns". But the classificatory model the DSM has been using since 1952 is harshly criticized as woefully inadequate by many scholars and practitioners.

The DSM is categorical. It states that personality disorders are "qualitatively distinct clinical syndromes" (p. 689). But this is by no means widely accepted. As we saw in my previous article and blog entry, the professionals cannot even agree on what constitutes "normal" and how to distinguish it from the "disordered" and the "abnormal". The DSM does not provide a clear "threshold" or "critical mass" beyond which the subject should be considered mentally ill.

Moreover, the DSM's diagnostic criteria are ploythetic. In other words, suffice it to satisfy only a subset of the criteria to diagnose a personality disorder. Thus, people diagnosed with the same personality disorder may share only one criterion or none. This diagnostic heterogeneity (great variance) is unacceptable and non-scientific.

In another article we deal with the five diagnostic axes employed by the DSM to capture the way clinical syndromes (such as anxiety, mood, and eating disorders), general medical conditions, psychosocial and environmental problems, chronic childhood and developmental problems, and functional issues interact with personality disorders.

Yet, the DSM's "laundry lists" obscure rather than clarify the interactions between the various axes. As a result, the differential diagnoses that are supposed to help us distinguish one personality disorder from all others, are vague. In psych-parlance: the personality disorders are insufficiently demarcated. This unfortunate state of affairs leads to excessive co-morbidity: multiple personality disorders diagnosed in the same subject. Thus, psychopaths (Antisocial Personality Disorder) are often also diagnosed as narcissists (Narcissistic Personality Disorder) or borderlines (Borderline Personality Disorder).

The DSM also fails to distinguish between personality, personality traits, character, temperament, personality styles (Theodore Millon's contribution) and full-fledged personality disorders. It does not accommodate personality disorders induced by circumstances (reactive personality disorders, such as Milman's proposed "Acquired Situational Narcissism"). Nor does it efficaciously cope with personality disorders that are the result of medical conditions (such as brain injuries, metabolic conditions, or protracted poisoning). The DSM had to resort to classifying some personality disorders as NOS "not otherwise specified", a catchall, meaningless, unhelpful, and dangerously vague diagnostic "category".

One of the reasons for this dismal taxonomy is the dearth of research and rigorously documented clinical experience regarding both the disorders and various treatment modalities. Read this week's article to learn about the DSM's other great failing: many of the personality disorders are "culture-bound". They reflect social and contemporary biases, values, and prejudices rather than authentic and invariable psychological constructs and entities.

The DSM-IV-TR distances itself from the categorical model and hints at the emergence of an alternative: the dimensional approach:

"An alternative to the categorical approach is the dimensional perspective that Personality Disorders represent maladaptive variants of personality traits that merge imperceptibly into normality and into one another" (p.689)

According to the deliberations of the DSM V Committee, the next edition of this work of reference (due to be published in 2010) will tackle these long neglected issues:

The longitudinal course of the disorder(s) and their temporal stability from early childhood onwards;

The genetic and biological underpinnings of personality disorder(s);

The development of personality psychopathology during childhood and its emergence in adolescence;

The interactions between physical health and disease and personality disorders;

The effectiveness of various treatments - talk therapies as well as psychopharmacology.